The following question was posted on the Facebook RPG Community group.  I thought it would be a good topic to discuss here as well, so here's the original question, and my response.  There were other responses, but it would be difficult to add them.  Crediting Ed Lazor with the Facebook post.

Ed Lazor wrote:How much are autographs worth, or more specifically, how much would I expect an autograph to increase the value of something?
For example, how much would be reasonable for the following people?

- Gary Gygax
- Dave Arneson
- Monte Cook
- Den Beauvais
- James Ward
- Frank Mentzer
- R.A. Salvatore
- Ed Greenwood
- Larry Elmore
- Jeff Easley

I’m sure there are more, but I’m just trying to give examples.

I’m asking for both buying and selling. In this case mainly for buying. I’d like to make fair and reasonable offers on autographed items.

Thanks!

Reply:

You likely won’t get much input on how much an autograph increases value, as many factors come into play. Some have already been mentioned. Generally, across all paper media, the value added is often substantial. We've routinely seen autographed copies from notable authors increase in value by 50-100% or more.

Key factors that influence value:

- The more collectible the item, the greater the impact of a signature. Rare or highly sought-after books see the biggest increases.
- Authentication is crucial. Provenance, witnessed signings, or certified autographs can boost value by 50% or more over an unverified signature.
- Signatures of key figures - especially those who have passed away or rarely signed are particularly valuable. Notable examples include Gary Gygax, Dave Arneson, Tom Moldvay, and Jean Wells from the early TSR days. The increase in value for items like these could be 100-200% or more.
- Inscribed vs. signature-only - Personal inscriptions can sometimes reduce the sales value but can increase it if the inscription was linked to a notable person. The increase in value for items that have notations like these could be 100-200% or more.
- Condition matters. The better the item’s condition, the higher the premium the autograph will command.
- Handwritten annotations or notes from the author/designer can dramatically increase value. If the autograph is accompanied by unique content, such as design notes or unpublished material, the value can skyrocket.

Here's a link to prior posts on the topic:

Signatures/Autographs

Thoughts?  Addition input?